Weld rod



Patented May 25, 1937 WELD ROD Anthony G. de Golyer, New York, N. Y"assignor to Vulcan Alloys Corporation, a corporation of Delaware NoDrawing. Application October 14, 1936, Serial No. 105,515

1 Claim.

This 'invention relates to a new alloy steel and relates particularly toan alloy steel containing molybdenum, tungsten, chromium, cobalt,manganese and boron, in the form of weld rod for the 5 production ofwelded surfaces or sections characterized by relatively high degree ofhardness, resistance to abrasion and resistance to deformation underimpact.

In many industrial operations it is desirable to apply a facing or inlayof hard wear resistant metal to parts of machinery or other equipmentexposed to excessive abrasion or impact. Various alloys and materialshave been proposed for this purpose. All'of such heretofore suggestedcompositions contain high percentages of alloy elements, together withat least 1% or more,

carbon. In general, weld metal deposited with such compositions may havehigh hardness, i. e.

approximately 400 to 500 Brinell hardness numbers, but all such depositsare relatively brittle chiefly by reason of the high carbon content,and, consequently are not-suitable for use on surfaces exposed to impactor shock as well as abrasion.

The object of the present invention is to provide an alloy which may be'readily'deposited by fusion welding, and which produces weld metalhaving relatively high strength, high resistance to deformation underimpact and relatively high hardmess.

I have found that an alloy composed of molybdenum 7% to 17%, tungsten 5%to 15%, chromium 3% to 9%, cobalt 3% to 10%, boron 0.75% to 2.25%,carbon 0.20% to approximately 1%, manganese 0.30% to 5% and theremainder substantially iron, possess high hardness, high strength andis extremely resistant to deformation under impact, when deposited bymeans of welding. The present alloy is particularly adapted for electricarc welding. Metal so deposited has a hardness of from 625 to 750BrinelLdepending, in part, upon the composition of the base metal andthe ratio of dilution. Weld deposits of the alloy which have beensubjected to cold work or hardness.

A distinct advantage of the present alloy is that it may be readilywelded on steel of any carbon content and'virtually all types of alloysteels, including 14% manganese steel. The combination of physicalproperties and characteristics possessed by this alloy render itparticularly valuable for facing or rebuilding surfaces of equipmentexposed to extreme conditions of abrasive wear and impact.

p The essential components of my alloy are molybdenum, tungsten,chromium, cobalt, boron, carbon, manganese and iron. The principalimpact usually show an appreciable increase in constituent is iron.Extensive experiments which I have made indicateconclusively that the.

alloy possesses the desired combination of high hardness and highresistance to failure under impact only when the essential componentsare present within the following percentages: molybdenum 7% to 17%,tungsten 5% to 15%, chromium 3% to 9%, cobalt 3% to 10%, boron 0.75% to2.25%, carbon 0.20% to approximately 1%, and manganese 0.30% to 5%, theremainder being principally iron. .It will be understood that smallamounts of silicon will be present as an impurity incidental tomanufacture. Also, minor amounts of sulphur, phosphorus and otherimpurities commonly found in alloy steels will usually be present asincidental impurities. The amounts ofallof such impurities should berestricted to maximum limits ordinarily prescribed for alloy steels.

One distinctive advantage of the present alloy-is that it makes possiblethe production, by welding, of deposits having high hardness without thepresence of large amounts of carbon, 1. e., greater than approximately1%, which render alloys of molybdenum, tungsten and iron extremelybrittle. I have found that the presence of appreciable amounts of boronin the alloy results in the production of weld deposits which are notonly hard, e. g., 650 Brinell or higher, but which are also remarkablytough, i. e., resistant to failure under impact.

As specific examples, alloys within the scope of the present inventionwhich I have found to be particularly suitable for deposition by weldingare the following: molybdenum 7%, tungsten 9%, chromium 4%, cobalt 9%,boron 1.10%, carbon 0.45%, manganese 2.10% and balance substantiallyiron; molybdenum 11%, tungsten 9%, chromium 5%, cobalt 6%, boron 1.40%,carbon 0.55%, manganese 2.85% and the balance substantially iron.

I wish to explain that in the present alloy molybdenum and tungsten arenot equivalents, but that each of these elements performs certaindefinite functions, and in order to produce an alloy having incombination the desired physical properties and characteristics bothmolybdenum and tungsten must be present within the limits specifiedherein.

I claim:

A weld rod comprising a metallic composition containing molybdenum 7% to17%, tungsten 5% to 15%, chromium 3% to 9%, cobalt 3% to 10%, boron0.75% to 2.25%, carbon 0.20% to 1%, manganese 0.30% to 5%, and theremainder substantially iron..

ANTHONY (1'. DE GOLYER.

